Ore beneficiation process and apparatus



P. L. PAULL ORE BENEFICIATION PROCESS AND APPARATUS Dec. 8, 1959 2Sheets-Sheet 1 Filed March 3, 1954 Dec. 8, 1959 P. L. PAULL 2,916,213

om: BENEFICIATION PRocEss AND APPARATUS Filed March s, 1954 2sheets-sheet 2 United Se@ Patient* oRn BENEFICIATION PROCESS ANDAPPARATUS Peter lL. Paull, Norwalk, Conn., assignor to TexacoDev'elopment Corporation, New York, N.Y., a corporation of DelawareApplication March 3, E1954, Serial No. 413,806

2'5 Claims. (Cl. 241-5) The present invention relates to a novel methodof and apparatus. for beneiiciating -ore Aso as vto separate particleswhich are richv in desired components from those that are poor.

Briey, my novel method involves first forming a flowable mixture such asa slurry of relatively coarse particles of an ore in a vaponzable liquidsuch as water, continuously passing this slurry into an initial portionof an elongated uid conduit, heating the slurry to vaporize liquid andform a dispersion of solid particles in hot vapor such as steam, andpassing the resulting dispersion through a latter portion of the fluidconduit at high velocity in turbulent ow to cause the particles toimpinge against one another and disintegrate to relf atively neparticles, some of which are rich and others poor in the desiredmineral. Y

The fine ore particles are continuously fed from the fluid conduit to aseparator wherein the rich particles are separated from the poor andcollected as a concentrate. Separation can be accomplished in anysuitable way, as by magnetic separation when there is a substantialdifference between the magnetic attractabilities of the rich and poorparticles, or by flotation wherein the rich particles are separated fromthe gangue on the basis of dif' ferences in their real or apparentspecific gravities in a liquid such as water.

My invention is highly advantageous because it is a rapid, economical,and continuous integrated operation combining size reduction of the'orewith concentration of the desired mineral. Also, as will appearhereinafter, the invention is surprisingly eicient because itincorporates various steps involving the multiple utilization of processfluids in different, parts of the method, and the recycling of rejectedmiddlings to improve recovery. Another important advantage is that sizereduction of the ore can be accomplished with but little wear on theapparatus, and in such a way that contamination of the ore withundesirable ingredients is avoided.

In the drawings:

Figs. l, 2, and 3 are schematic ow diagrams showing three modificationsof apparatus for performing one embodiment of the invention, whereinsize reduction is cornbined with flotation for the separation of richparticles from poor; and

Figs. 4 and 5 are schematic flow diagrams showing two modifications ofapparatus wherein size reduction is combined with magnetic separation.

In the following description the slurry liquid is exemplied by water,but under some circumstances other liquids such as petroleum distillatesor liquid refrigerants can be used. Examples of the former are keroseneand lubricating oil. Examples of the latter are ammonia, sulfurvdioxideand propane.

As shown in Fig. l, ore particles which have been previously crushed ina jaw crusher to a' relatively coarsev Patented Dec. 8., 1959considerably but generally is less than 2:1 by volume, often being 1:1.Continuous feed of ore particles and Water to tank 11 in the selectedproportions is advantageous.

This slurry is pumped continuously by a pump 13 at a linear velocity of1/2 to 10 feet per second into the initial portion of an elongatedconduit or tubular zone, including a long heated tube 17 located withina heater 19 which may be tired in any desired way, as by oil or gas.Tube 17 can be coiled, or in the form of parallel straight tubesconnected together by return bends, so as to effect space economy inheater 19; and the tube may be composed of two or more sections locatedin several individual heaters.

In the initialportion of tube 17 the slurry is rapidly heated to atemperature above the boiling point of Water and a dispersion of coarseore particles in steam is formed. This dispersion passes at a highvelocity in excess of feet per second, through the latter portion of thetube 17 and continues through a pair of branch tubes 21 and 23 fromwhich it is discharged as a pair of opposed mutually impinging highvelocity jets through a pair of diametrically opposed nozzles 25 and 27located Within a low pressure grinding chamber 29. Tubes 21 and 23, andnozzles 25 and 27 constitute part of the tubular zone along with tube17. Velocity in tube 17 advantageously is kept below 100 feet per secondto reduce erosion of the tube by the solid particles, but much highervelocities may be used where erosion is not an important factor.

Some size reduction occurs as the result of turbulence and mutualimpingement of particles on one another before the ore particles reachthe nozzles, but most of the grinding results from impact of the twojets against one another due to the high velocity and turbulent ow whichcauseparticles to collide with great force. Relative velocities of thetwo jets are double that of a single jet, yet erosion difficulties areavoided because impingement reduces velocities below detrimental valuesbefore the particles strike the walls of the grinder. Particle sizes ofthe ground ore are such that substantially all pass through a 200 meshU.S. Standard screen (-200 mesh), and many-are as line as 5 microns.

From grinding chamber 29 the dispersion of ultra-fine particles in'steamthen passes by way of a conduit 31 to a condenser 33 whereincondensation of the dispersion back to a slurry is accomplished bypassing a cooling liquid such as water into the condenser through aconduit 35 and out through a conduit 37 for indirect heat exchange withthe dispersion to reduce its temperature below the boiling point ofwater, say to a temperature between and 180 F.

The hot reconstituted slurry then ows through a con-- duit 39 into aflotation machine tank 41 to form a pulp which is -agitated violently bymechanical stirring and/or by the bubbling of gas such as airtherethrough. Air

' is supplied by a conduit 43 and distributed through a porous septum`45 forming the bottom of the tank and inclined toward one side for theaccumulation of settled unfloated material. A froth -47 forms on the topof the liquid pulp 49 and carries therewith one of the compo-l nents ofthe ore, usually the rich one, this froth being continuously removed byflow into a trough 51. The settled material at the bottom of the tank,usually the poor particles or gangue, is removed as a slurry through.

a conduit 53.

It is often found that the settled gangue leaving through conduit 53still contains some valuable minerali; content. This can be recovered bypumping the gangueA slurry through a conduit 54 back to the slurrytank11 to mix with fresh slurry and be recycled as described,` above,whereby the sangue particles are reduced still further in size.Alternatively or concurrently, 'gangle slurry may be injected into thedispersion in heater tube 17 through a conduit 56 to cause shock coolingand rewetting of the solid particles, whereby size reduction isaccentuated. Suliicient heat is supplied to vaporize the liquid afterthe rewetting.

In general the desirable concentration of solids in the pulp within`flotation tank 41 will be less than in slurry tank 11. Therefore, whenthe reconstituted slurry is passed into tank 41 it may require dilutionby the addition of water to reduce the concentration of solids to aboutZtl-40% by volume. Dilution is readily accomplished in an ecient andeconomical manner with the condenser heat exchange liquid, as by passingit through a conduit 55 into the conduit 39 in amounts regulatedautomatically byyconventional flow controllers.

Separation by flotation occurs more etfectively at high temperaturesthan at low because a rise in temperature normally increases reactionvelocities; aids completion of reactions involving decomposition,solution of solids, or formation of gas as one of the reaction products;and reduces the viscosity of flotation agents such as oils, thus aidingcoating of ore particles. Such a relatively high temperature, of course,is an important advantage of the method described above wherein hightemperature grinding is employed and a slurry is passed at a hightemperature into the flotation machine.

An important factor in froth flotation is the employment of suitableaddition agents in the pulp to cause selective separation of rich andpoor ore particles by means of a froth which acts to float off someparticles of ore while permitting others to sink to the bottom. Amongsuch addition agents are collecting agents, conditioning agents, andfrothing agents, specific examples of which are well known to the art asdescribed on pages 12-03 to 12-47 of the Handbook of Mineral Dressing byArthur F. Taggart, published by John J. Wiley and Sons, Inc., copyright1945. Such agents can be continuously added by feeding them directly tothe flotation tank 41, or by incorporating them in the initial slurry intank 11 for passage through the grinding portion of the system beforeentering the flotation tank, or by introduction at any intermediatepoint. By incorporation with the slurry before vaporization theindividual particles lcan -be uniformly coated. The quantity requiredyis very small, generally ranging from 0.05 to 1.0 pound per ton of pulpunder treatment.

Example I Referring to Fig. 1, concurrent grinding and notationconcentration 'of molybdenite illustrates the present invention. vAn 89%by weight slurry of 14 mesh molybdenite ore in water is passed at a rateof 3300 pounds per hour through 800 feet of '1K2 inch heater pipe 17(arranged in four heaters as parallel straight pipes connected by returnbends) to an opposed jet grinder 29 having 3A6 inch LD. (insidediameter) nozzles and thence to a condenser 33. Air is bled into heaterpipe 17 through conduit 57 to condition the molybdenite.

Thepressures in pounds per square inch are 1100 at the entrance to theheater pipe, 543 at the nozzle inlets, and atmospheric at the condenser.The temperature at the nozzle inlets is 751 F. The velocity ahead of thenozzles is about 100 feet per second, but sonic Velocity is reached inthe nozzles.

The L200 mesh ground ore slurried in water from the steam condensationis then passed to a ilotation tank 41 to which is continuously addedenough water from conduit y55 to reduce the ore concentration to 30% byvolume. Also there is continuously added to thepulp in 'the lflotationtank 4a mixture of C-Cm aliphatic alcohols, fuel'oil, andpine oil (424:2parts by'volume, respectivelylat a rate of 0.5 pound per ton of pulp.

fAgitatio'n of the pulp by air effects the desired otation of`molybdenite particles from the gangue particles.

zetema i f Referring to Fig. of the drawings, a grinder 29' identicalwith that of Fig. l is preceded by identical heater tubing and slurrytank equipment, which have been omitted for simplicity. The dispersionfrom grinder 29 ows through conduit "31 into a centrifugal separator 61such as a conventional cyclone separator within which all or part of thesteam or other vapor is separated and passes off the top through aconduit 63.` Solid material passes out the vbottom through an outlet`65, is picked up by a stream of water from a conduit 67, and carriedthrough a conduit 69 into the flotation tank 41 for concentration of themineral. Y

Separator 61 is provided with external condensing' coils 71 which can besupplied with cooling water through a conduit 73 leading from theconduit 67 on the upstream side of a control valve 75 and then connectedback into conduit 67 downstream of valve 75. With this construction apart of the steam can be ondened in separator l61 so that'a wet mass ofground ore is def livered through outlet 65 for better mixing with thediluting water from conduit y67 prior to entering tank 41'.

The steam leaving the top of separator l61 passes by conduit 63 to anair aspirator 79 wherein a substantial volume of air is aspirated andpasses with the steam through conduit 81 and a conduit `8.3 into thevoid 85 below a porous septum 87. The mixture of steam and air thenpasses through the septum to agitate the pulp 89 and cause separation ofthe ore `ingredients by iiotation. Auxiliary air may be supplied throughconduit 91. Sometimes agitation by the steam alone is sumcient, and thenthe aspirator 79 is eliminated and steam alone enters void 85.

As in Fig. l, foam laden with mineral particles is taken oi the top by atrough 51'; and settled particles in slurry form are taken .olf thebottom through a conduit 53' and may be recycled to the slurry tankand/or heater tube if desired.

Referring .to Fig. 3 of the drawings, a `grinder 9,5 is supplied with adispersion in the manner of Fig. l. Grinder is a convergent-divergentnozzle which takes the relatively low velocity dispersion from conduit17 and accelerates it tremendously so .as to develop supersonic velocity(greater than `1000 feet p er second) and great turbulence whereby thesolid particlesimpinge forcibly against one another and are reducedgreatly in size. The -powdered dispersion then passes to a centrifugalseparator 97, such as a conventional cyclone, which is so designed as toseparate out oversized solid particles which leave the bottom throug'hanoutlet 99 and can be returned Vto theslurry tank and/ or heater tube forrepetition of the lgrinding cycle, if desired. 'The dispersion of fineparticles in steam passes off the top through a conduit 101 and isdelivered to agenerally'horizontal header 1013 having 'a plurality ofnozzles '105 for passing the dispersion into the bottom o'f the pulp 107'in a tlotation tank 109. Auxiliary cold water to reduce theconcentration of the slurry is added through a conduit '1.11. Froth andsettledparticles are removed as described prerviously.

In the Fig. 3 modilication uniform distribution of the solid particlesinthe pulp 107 is obtained while the steam concurrently agitates thepulp and 'heats it so as to effect an efficient flotation operation.`Much of the steam, of course, vis condensed in the pulp.

Example II Referring to Fig. 3, a 59% by weight slurry of 14 meshapatite orein water is passed ata rate of 1732 pounds perhour through800 feet of l inch heater pipe, as in Example I, to aconvergent-divergent nozzle 95 having a 1A inch throat, `and .thence toa4 Ainch I.D. scalping cyclone97. vr1`he pressur;es sin pounds ,persquareinch. are 1'092 at .the entrance to .theheater pipe, 578 at the'nozzleinlet, and .l0 .at the cyclone. The tempera- UfQC the nozzle 'inletJis.7 5 0 F ,at the cyclone entrance 15 741 F., and at the bottom' ofthe cyclone 700 F. Supersonic velocity is reached in the nozzle.

The scalped steam dispersion of -200 mesh ground ore from the top o-fcyclone97 then flows into a llotation `machine 109 to which iscontinuously added enough cold water to reduce the ore concentration to28% by volume. Also there is continuously bled into the pulp at a rateof 0.2 pound per ton of pulp a flotation reagent formed by 2 pounds talloil fatty acid, 4 pounds light fuel oil, 1/2 `pound of caustic soda, and`1 pound of turpentine. The concentrate of phosphate is iloated oliwhile the gangue settles to the bottom.

By way of illustration the principles of that portion of the inventioninvolving flotation have beendescribed `above with reference to frothllotation. It is evident, however, that theyfalso apply to other typesof flotation such as skin llotation, bulk oil flotation, andgranulation.

VVThere are many. different types of ores 4which can be concentrated bythe combined grinding and ilotation methods described above. In general,if two minerals diier to the extent that one contains a substantialamount of a particular metallic element or acid ion which is absent inthe other, the two may be separated by flotation. Forexample, single orvmixed suliides can be separated from the usual rocky gangues. Theoxidized heavymetal minerals and the rocky mineralsof the non-silicateseries can be separated from each other and from the silicate minerals.'Coal and graphite are readily separable from the rock-forming minerals.Quartz and `other silicates can be lloated in the presence of metallicoxides and mineral salts of the alkaline earths.

Among specific sulfide minerals which can be concentrated by flotationare cinnabar, copper suliides, chalco-V cite, chalcopyrite, galena, andmolybdenite. Others, of the non-sulfide variety, are native metals suchas gold, silver and copper; and such oxides as bauxite, cassiterite,chromite, manganese oxides, iron oxides, rutile, alunite, cerussite,scheelite, vanadinite, calcite, dolomite, lluorspar, and 'variousphosphates such as apatite and podolite.

Silicates also can be concentrated by flotation, for exi ampleandalusite, 4beryl ore, brucite, feldspar, mica, and

kyanite.

Oxidation is a form of activation for suliide minerals often employed asa preliminary to flotation. When using the present invention on sulfideores, such oxidation can be accomplished readily in the heater tube 17by bleeding in air or oxygen through a conduit 57 to react l with thesulde and prepare it for ilotation.

Fig. 4 shows an arrangement of apparatus wherein an integratedcombination of grinding and magnetic separation of the ore isaccomplished. A slurry of about 50% ore in water by volume is made upcontinuously in a slurry tank 115 and pumped through a conduit 117 intothe initial portion lof an elongated iluid conduit comprising a tube 119located Within a heater 121 fired in any desired way, as by oil or gas,all as described in connection with Fig. l As the slurry passes throughtube `119 water is vaporized to form in the latter portion of the tube adispersion which ilows at a velocity in excess of 25 feet per second toa grinder 123 comprising a convergent-divergent nozzle forming a part ofthe lluid conduit. Supersonic velocity and great turbulence are thusproduced in the nozzle and the particles are disintegrated by collisionwith one another.

The dispersion then passes through a conduit 125 into a centrifugalvseparator A127. Steam leaves at the top of separator 127 through aconduit 129, while substantially dry ground ore leaves the bottomthrough a conduit 131 and enters a rotating cooling drum 133 over theoutside of which water is sprayed by a series of distributing nozzles135 to cool the ore down to a'temperature preferably below 100 C.

From drum 133 the ore enters a hopper 135 and passes onto the peripheryof a magnetic separator drum 137 whichrotates counterclockwise while amagnet 139 within the `drum rotates clockwise. The relativelynonmagnetic middling .material is carried counter-clockwise and ilowsoffvthe side of the drum into a receptacle 141, while the magneticconcentrate is carried clockwise and taken off the other side of thedrum by a clockwise rotating magnetic collector wheel 143. Severalsuitable dry magneticl separators are described in the aforementionedTaggart volume on pages 13-15 to 13-l9.

Some ores contain a mineral which is not suiciently magnetic as mined,but which can be converted to a more magnetic condition by a suitableroasting treatment. This can be readily accomplished in my method byintroducing through a conduit 145 into the latter portion of the heatercoil 119 a suitable gas such as air, oxygen, nitro-gen, or a reducingatmosphere such as hydrogen, carbon monoxide, or natural gas so as toreact with the ore at the high temperature of the coil.

Hematite can be changed to magnetic Fe304 by extrac- -tion of the oxygenat temperatures ranging between 370 and 600 C. This can be done bystrong heating in the air, less heat in a reducing atmosphere, and stilllower heat when there is intimate admixture with a lreducing substancesuch as hydrogen or carbon. From 5-10% by weight of carbon or equivalentreducing agent should be used. o

Pyrite may lbe converted either to FeqSs or to Fe304, both of which arehighly magnetic. The former is produced by introducing air while heatingat about 400 C. Further roasting at 50W-600 C.. with limited air and anatmosphere of CO, H2, and SO2 results in conversion to F8304. i

Manganese and chromium ores can be improved mage, netically by bleedingin nitrogen at the temperature of the coli.

Referring again to Fig. 4, the etliciency of the operation is greatlyimproved by reusing the water collected below cooling drum 133 in a sump144. Thiscan be done by pumping it by way of a conduit 146 through apreheater 147 to the slurry tank 115 and/or heater tube 119.Alternatively, the water from sump 144 can be passed to receptacle 141to form -a slurry with the middling, and 4this slurry can be pumped byway of a conduit 148' through a preheater 150 to the slurry ltank 115and/or heater tube 119. Preheaters 147 and 150 are supplied with heatingstearn by connection to the conduit 129 which carries the o steam fromcyclone separat-or 127.

Example Ill Referring to Fig. 4, a 58% by weight water slurry of -14mesh zinc ore containing 35% franklinite along with non-magneticminerals is passed at a rate of 1884 pounds per hour through 800 feet of1/2 inch heater pipe, as in Example I, to a convergent-divergent nozzle123 having a 1A; inch throat, and thence to a cyclone separator 127wherein steam passes olf the top and substantially dry fine oreV (-200mesh) leaves at the bottom.

The pressures in pounds per square inch'are 1073 at the entrance to theheater pipe, 596 at the nozzle inlet, and substantially atmospheric atthe cyclone. The temperature at the nozzle is 759 F. Supersonic velocityis reached in the nozzle.

The dry hot ore from cyclone 127 passes through cooler 133 wherein itstemperature is reduced to about F., and into hopper 135 from which it isfed onto a magneticseparator surface 137. Franklinite is concentratedunder the influence of the magnet, and the balance of the ore passes offas middling, which may be discarded or recycled, as desired. ergized at12.5 volts with a current of 14.0 amperes.

Referring to Fig. 5, an arrangement of apparatus for performing a wetmagnetic separation by my novel method is shown. :A slurry is made up intank 149, passes through a heater tube 151 to which a suitable gas may'be supplied through a conduit 153, as described in con-` V7 nectionwithFig.,4, Land then. theresulting dispersion enters an opposed nozzlegrinder 155 of the type described in connection with Figs.,1 and v2.

The dispersion of extremely 'ine particles of ore in steam then enters acondenser 157 wherein it is converted back to a hot slurry which is'transferred by a conduit 159 onto the `surface of an inclined clockwiserotating belt 161. The top of belt 161 passes in close proximity to anelongated magnet 163. Suitable wet magnetic separators are describedinthe `aforementioned Taggart volume, t

pages 13-19 to 13-32.

As the belt 161 revolves the magnetic particles o-f ore are carried overthe top and discharged at 165 as the concentrate, while the non-magneticparticles fow. E the. bottom at 171 with the slurry Water. Meanwhile,condenser water from 157 ows by way of a conduit 1167 to a header 169having a plurality of discharge nozzles arranged across the width ofbelt 161 for delivering a plurality of streams of water von the beltto.help wash the non-magnetic material to the bottom.

Non-magnetic middling particles from the bottom of belt 161 enter areceptacle 173 along with the water, and the resulting slurry .is pumpedthrough a conduit 175 back to slurry tank 149 for further grinding alongwith fresh ore .to liberate magnetic material from associated gangue andprepare it for magnetic separation as described above.

Example I V Referring to Fig. a 66% by weight slurry of -14 meshtaconite iron ore in water is passed at a rate of 2307 pounds per hourthrough 1000 feet of 1/2 inch heater pipe 151, as in Example I, to anopposed jet grinder 155 having FAG inch LD. nozzles, and thence to acondenser 157 wherein a slurry is reformed wherein the particles aresubstantially all 200 mesh.

'.Ihe pressures in pounds per square inch are 1642 at the entrance tothe heater pipe, 1224 at the nozzle inlets, and substantiallyatmospheric at the condenser. The temperature at the nozzle inlets is751 F. Sonic velocity is reached in the nozzles, but the velocityupstream is not more than 100 feet per second to avoid erosion.

The -200 mesh ground taconite ore slurry passes onto belt 161 forseparation of the m'agnetitev (which passes `olf the top) from thesiliceous gangue (which ilows down and passes off the bottom.)

Many different ores are amenable to magnetic concentration by my novelmethod, the principal ones being those containing the iron mineralmagnetite. For example, the iron content of taconite, consistingpredominantly of silica combined with a relatively small amount ofmagnetite, can be readily separated. Other separations which can beaccomplished in this way are roasted hematite and limonite from silica;roasted siderite from siliceous and carbonaceous gangue; roasted pyritefrom blende unaltered in the roasting; pyrrhotite from blende, and fromquartz and basic silicates. Other commercial separations are:franklinite from Willemite, zincite, and calcite; pyrolusite andpsilomelane from siliceous gangue and limonite; chromite from silicates;rutile from apatite; copper carbonates from siliceous gangue; wolframitefrom cassiterite; magnetite and ilmenite from monazite sands; ilmenitefrom cassiterite concentrate; rutile, brookite, and ilmenite fromorthoclase feldspar; and wolframite from a tungsten-bismuth concentrate.

Obviously, many modifications and variations of the invention, ashereinbefore set forth, may be made without departing from the spiritand scope thereof, and therefore only such limitations should be imposedas are indicated in the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are dened as follows:

1. A method of producing a finely-divided mineral concentrate from amass of relatively coarse particles of an ore which contains saidmineral associated withvother bulent flow to-cause said particles toimpinge against one another and disintegrate'to relatively iineparticles, some of said ne particles being rich and others poor in saidmineral; atleast partially condensing said steam and forming a owablemixture of said tine particles in the resulting water; and thenseparating said rich particles from said poor particles in said flowablemixture and collecting said rich particles to form said concentrate.

2. A method in accordance with claim 1, wherein there is a substantialdiierence between the magnetic attractabilities of said mineral and saidmaterial, and wherein separating said rich particles from said poorparticles is accomplished by subjecting said particles to a magneticfield.

3. A` method in accordance with claim 1, also comprising maintaining incontact with said ore during said heating step an atmosphere of a gaswhich promotes the magnetic attractability of a constituent of said ore,thereby assuring a substantial difference between the magneticattractabilities of said mineral and said material; and whereinseparation is accomplished by subjecting said particles to a magneticfield.

4. A method of producing a timely-divided mineral concentrate from amass .of relatively coarse particles of an ore which contains saidmineral associated with other material, said method comprising forming aflowable mixture of said particles in a vaporizable liquid; passing saidmixture into an initial portion of an elongated iluid conduit; heatingsaid mixture in said fluid conduit to vaporize liquid and form adispersion of said particles in hot vapor; passing said dispersionthrough a latter portion of said fiuid conduit at high velocity inturbulent flow to cause said particles to impinge against one anotherand disintegrate to relatively tine particles, some of said tineparticles being rich and others poor in said mineral; separating vaporfrom the iine particles of ore to provide a substantially dry ore;passing said dry ore to a magnetic separator; and separating said richparticles from said poor particles by subjecting said particles to amagnetic field in said magnetic separator. j

5. A method of producing a finely-divided mineral concentrate from amass of relatively coarse particles of an ore which contains saidmineral associated with other material, said method comprising forming aowable mixture of said particles in a vaporizable liquid; passing saidmixture into an initial portion of an elongated fluid conduit; heatingsaid mixture in said fluid conduit to vaporize said liquid and form adispersion of said particles in hot vapor; passing said dispersionthrough a latter portion of said uid conduit at high velocity inturbulent flow to cause said particles to impinge against one anotherand disintegrate to relatively fine particles, some of said fineparticles being rich and others poor in said mineral; separating hotvapor from the fine particles of ore to provide a substantially dry ore;cooling said ore; passing said dry ore in a relatively cool condition toa magnetic separator; and separating said rich particles from said poorparticles by subjecting said tine particles to a magnetic field in saidmagnetic separator.

6. A method in accordance with claim 5, wherein cooling of said ore isaccomplished by passing a owing body of said vaporizable liquid inindirect heat exchange relationship therewith, said method comprisingthe additional step of passing said vaporizable liquid thereafter intomixture with said relatively coarse particles for forming said slurry.`Y

k7. A method in accordance with claim 6also comprising passing saidseparated hot vapor in heat exchange relationship with said vaporizableliquid after fcooling said ore therewith to preheat said vaporizableliquid prior to forming said slurry therewith.

rEl. A method of producing a finely-divided mineral concentrate from amass of relatively coarse particles of an ore which contains saidmineral associated with other material, said method comprising forming aowable mixtures of said particles in water; passing said mixture into aninitial portion of an elongated iluid conduit; heating said mixture insaid fluid conduit to vaporize liquid and form'a dispersion of saidparticles in hot vapor; passing said dispersion through a latter portionof said fluid conduit at high velocity in turbulent flow to cause saidparticles to impinge against one another and disintegrate to relativelyine particles, some of said line particles being rich and others poor insaid mineral; condensing vapor in said dispersion to form a new fiowablemixture of said fine particles by passing a cooling liquid in heatexchange relation therewith; passing said new mixture to a magneticseparator; separating said rich particles from said poor particles insaid owable mixture by subjecting said fine particles to a magneticfield; passing said cooling liquid from said 'condensing step to saidmagnetic separator and washing therewith the material on said seplarator to assist the separation of rich and poor particles from oneanother.

9. A method in accordance with claim 1 wherein said rich and poorparticles are separated from one another by dotation.

10. A method of producing a nely-divided mineral concentrate from a massof relatively coarse particles of an ore which contains said mineralassociated with other material, said method comprising forming aflowable mixture of said particles in Water; passing said mixture intoan initial portion of an elongated uid conduit; heating said mixture insaid uid conduit to vaporize water and form a dispersion of saidparticles in steam; passing said dispersion through a latter portion ofsaid fluid conduit at high velocity in turbulent flow to cause saidparticles to impinge against one another and disintegrate to relativelyne particles, some` of said fine particles being rich and others poor insaid mineral; condensing steam in said dispersion to form a new owablemixture of said tine particles; passing said new mixture to a dotationseparator; and separating said rich and poor particles from one anotherby flotation.

1l. A method of producing a finely-divided mineral concentrate from amass of relatively coarse particles of an ore which contains saidmineral associated with other material, said method comprising forming aowable mixture of said particles in a vaporizable liquid; passing saidmixture into an initial portion of an elongated fluid conduit; heatingsaid mixture in said fluid conduit to, vaporize liquid and form adispersion of said particles in hot vapor; passing said dispersionthrough a latter portionof said fluid conduit at high velocity inturbulent ow to lcause said particles to impinge against one another anddisintegrate to relatively fine particles; some of said ne particlesbeing rich and others poorin said mineral; separating vapor from saiddispersion; passing said ne particles to a flotation separatorcontaining a pulp of such fine particles in a liquid; and passing saidvapor into said ilotation separator for agitating said pulp to effectseparation of said rich and poor particles from one another.

12. A method in accordance with claim `11, also comprising aspiratingair with said vapor, and passing both said air and said vapor into saidseparator for agitating said pulp.

13. A method in accordance with claim 11, also cornprisingfcondensingpart of the vapor of said dispersion,

and passing the condensed vapor with said ne particlesA to said otationseparator.

14. A method in accordance with claim- 13 wherein said part of saidvapors is condensed by passing water in indirect heat exchangerelationship therewith, said method also comprising passing said waterthereafter to said flotation separator with said condensed vapor andisaid ne particles to make up said pulp.

15. A method of producing a nely-divided mineral concentrate from a massof relatively coarse particles of an ore which contains said mineralassociated with other material, said method comprising forming aflowable mixture of said particles in a vaporizable liquid; passing saidmixture into an initial portion of an elongated iiuid conduit; heatingsaid mixture in said fluid conduit to vaporize said liquid and form adispersion of said particles in hot vapor; passing said dispersionthrough a latter portion of said fluid conduit at high velocity inturbulent ow to cause said particles to impinge against one another anddisintegrate to relatively ne particles, some of said ne particles beingrich and others poor in said mineral; passing said dispersion into apool of pulp in a dotation separator to add said fine particles theretowhile agitating said pulp with said vapor; and separating said richparticles from said poor particles in said separator and collecting saidrich particles to form said concentrated 16. Apparatus for producing afinely-divided mineralv concentrate from a mass of relatively coarseparticles of an ore which contains said mineral associated with othermaterial, said apparatus comprising a slurry tank; an`

elongated iluid conduit connected to said slurry tank, said fluidconduit comprising an initial portion to receive slurry, and a latterportion for carrying a dispersion of ore in vapor at high velocity inturbulent flow to cause said.`

particles to impinge against one another and disintegrate to relativelyiine particles, some of said fine particles being rich and others poorin said mineral; a condenser connected to said iiuid conduit forcondensing said dispersion to a slurry; and a magnetic separator inposition for receiving slurry from said condenser for separating saidrich and poor particles from one another.

17. Apparatus for producing a finely-divided mineralI to relatively fineparticles, some of said fine particles being rich and others poor insaid mineral; a condenser connected to said fluid conduit for condensingsaid dispersion of a slurry, and a floatation separator connected tosaid condenser for separating said rich and poor particles from oneanother by selective flotation.

18. A method of producing a finely divided mineral concentrate from amass of relatively coarse particles of an ore which contains saidmineral associated with other material, said method comprising forming aowable mixture of said particles in water; passing said mixture into aconfined heating zone; heating said mixture in said zone sufiiciently tovaporize said water thereby forming therein a dispersion of saidparticles in steam; disintegrating said particles of ore to relativelytine particles by passing said dispersion through a succeeding Zone ofhighy Velocity ow and subjecting the ilowing stream therein toturbulence and a high velocity, some of said fine particles being richand others poor in said mineral; at least partially condensing saidsteam and forming a ilowable mixture of said ne particles in theresulting water; and then separating said rich particles from said poorparticles in said ilowable mixture and collecting said rich particles toform said concentrate.

19. A method in accordance with claim 18 wherein said dispersion ispassed at high velocity in turbulent owby discharging said dispersion inat least two mutually* opposed and impingingjets. v t

20. Apparatus for producing a mineral concentrate from a mass ofrelatively coarse particles of an ore which contains said mineralassociated with other material, said apparatus comprising rst means -forforming a mixture of ore particles with liquid; a fiuidconduit connectedto said means, said uid conduit comprising an initial portion to receivesuch mixture, and a latter portion for carrying a dispersion of ore invapor at high velocity in turbulent ow to cause said particles toimpinge against one another and disintegrate to relatively tineparticles, some of said tine particles being rich and others poor insaid mineral; second means for bringing a heating medium into heatexchange relationship with said mixture in said conduit to vaporize saidliquid and form said dispersion; a condenser connected to said iluidconduit for condensingy said dispersion to reform a owable mixture ofore particles in liquid; and a separating device in position forreceiving mixture from said condenser for separating said rich and saidpoor particles from one another.

21. Apparatus for producing a mineral concentrate from a-mass ofrelatively coarse particles of an ore which c ontains said mineralassociated with other material, said apparatus comprising rst means forforming a mixture of ore particles with liquid; a fluid conduitconnected to said first means, said uid conduit comprising an initialportion to receive such mixture, and a latter portion for carrying adispersion of ore in vapor at high Velocity in turbulent flow to causesaid particles to impinge against one another and disintegrate torelatively fine particles, some of said ne particles being rich andothers poor in said mineral; second means for bringing a heating mediuminto heat exchange relationship with said mixture in said conduit tovaporize said liquid and form said dispersion; third means connected tosaid uid conduit for separating vapor from said fine particles; aoatation separator in position to receive tine particles from said thirdmeans for separating said rich and poor particles from one another byselective oatation, said oatation separator containing a pool of liquid;and conduit means connecting said third means to said Alioatationseparator for conducting vapor from said third means to said separatorfor introduction into said pool of liquid to agitate said pool.

22. Apparatus for producing a mineral concentrate from a mass ofrelatively coarse particles of an ore which contains said mineralassociated with other material, said apparatus comprising iirst meansfor forming a mixture of ore particles with liquid; a uid conduitconnected to said iirst means, said fluid conduit comprising an initialportion to receive such mixture, and a latter portion for carrying adispersion of ore in vapor at high velocity in turbulent flow to causesaid particles to impinge against one another and disintegrate torelatively ne particles, some of said line particles being rich andothers poor in said mineral; second means for bringing a heating mediuminto heat exchange relationship with said mixture in said conduit tovaporize said liquid and form said dispersion; a oatation separatorcomprising a tank having a pool of liquid therein; and conduit meansconnecting said latter portion of said fluid conduit to said floatationseparator to conduct said dispersion into said pool of liquid below thesurface thereof for simultaneously introducing tine ore particles andagitating said pool of liquid, to elect separation of rich and poorparticles from one another by selective iloatation.

23g Apparatus for producing a mineral concentrate from a mass ofrelatively coarse particles of an ore which contains said mineralassociated with other material, said apparatus comprising iirst meansfor forming a mixture of ore particles with liquid; a uid conduitconnected to said `first means, said fluid conduit comprising an initialportion to receive such mixture, and a latter portion for carrying adispersion of ore in vapor at high velocity in. turbulent 110W t0 .CauseSaid particles t0 impnge against Otis @ether and disintegrate torelatively flue Particles, some of said tine particles being rich andothers poor in said mineral; second means for ybringing a heating mediuminto heat exchange relationship with said mixture in said conduit tovaporize said liquid .and form said dispersion; third means connectedAto said fluid conduit for separating hot vapor from said dispersion; anore cooling device connected to said separator for receiving iine oreparticles therefrom, said device including means for passing coolingliquid in heat exchange relationship with said ore particles, and meansfor collecting used liquid; a separator `in position for receiving oreparticles from said cooler for separating said rich and said poorparticles from one another; conduit means for conducting liquid fromsaid pool back to a fore part of said apparatus; and means for passingsaid hot vapor from said third means in heat exchange relationship withsaid last named liquid for preheating said liquid.

24. A method of producing a finely-divided mineral concentrate from amass of relatively coarse particles of an ore which contains vsaidmineral associated with other material, said method comprising forming aflowable mixture of said particles in a vaporizable liquid; passing saidmixture into an initial portion of an elongated fluid conduit; heatingsaid mixture in said fluid conduit to vaporize liquid and form adispersion of said particles in hot vapor; passing said dispersionthrough a latter portion of said uid conduit at high velocity inturbulent flow to cause said particles to impinge against one anotherand disintegrate to relatively tine particles, some of said ne particlesbeing rich and others poor in said mineral; condensing vapor in saiddispersion to form a new flowable mixture of said iine particles bypassing cooling liquid in heat exchange relation therewith; thereafterpassing said cooling liquid into said new ilowable mixture to increasethe liquid content thereof; passing said new flowable mixture to afloatation separator; and separating said rich and poor particles fromone another by floatation.

25. Apparatus for producing a finely-divided mineral concentrate from amass of relatively coarse particles of an ore which contains saidmineral associated with other material, said apparatus comprising atank; an elongated uid conduit connected to said tank, said uid conduitcomprising an initial portion to receive a owable mixture, and a latterportion for carrying a dispersion of ore in vapor at high velocity inturbulent iow to cause said particles to impinge against one another anddisintegrate to relatively line particles, `some of said fine particlesbeing rich and others poor in said mineral; a condenser connected tosaid uid conduit for condensing said dispersion to a flowable mixture;and a magnetic separator in position for receiving owable mixture fromsaid condensor for separating said rich and poor particles from oneanother; and conduit means for conducting used cooling water from saidcondenser to a position adjacent said magnetic separator and fordischarging said liquid onto said separator.

References Cited in the le of this patent UNITED STATES PATENTS2,428,228 Keck Sept. 30, 1947 2,572,061 Sellers Oct. 23, 1951 2,612,320Croft Sept. 30, 1952 2,726,813 Asdell Dec. 13, 1955 2,763,434 StrasserSept. 16, 1956 FOREIGN PATENTS 683,318 Great Britain Nov. 26, 1952 OTHERREFERENCES Handbook of Mineral Dressing by Arthur F. Taggart, publishedby John I. Wiley and Sons, Incorporated, copyright 1945, pages 12-1 to12-47; pages 13-15 to 13-19 and pages 13-19 to 13-34.

1. A METHOD OF PRODUCING A FINELY-DIVIDED MINERAL CONCENTRATE FROM AMASS OF RELATIVELY COARSE PARTICLES OF AN ORE WHICH CONTAINS SAIDMINERAL ASSOCIATED WITH OTHER MATERIAL, SAID METHOD COMPRISING FORMING AFLOWABLE MIXTURE OF SAID PARTICLES IN WATER; HEATING SAID MIXTURE TOVAPORIZE WATER AND FORM A DIPERSION OF SAID PARTICLES IN STEAM; PASSINGSAID DISPERSION AT HIGH VELOCITY IN TURBUTLENT FLOW TO CAUSE SAIDPARTICLES TO IMPINGE AGAINST ONE ANOTHER AND DISINTEGRATE TO RELATIVELYFINE PARTICLES, SOME OF SAID FINE PARTICLES BEING RICH AND OTHERS POORIN SAID MINERAL; AT LEAST PARTIALLY CONDENSING SAID STEAM AND FORMING AFLOWABLE MIXTURE OF SAID FINE PARTICLES IN THE RESULTING WATER; AND THENSEPARATING SAID RICH PARTICLES FROM SAID POOR PARTICLES IN SAID FLOWABLEMIXTURE AND COLLECTING SAID RICH PARTICLES TO FORM SAID CONCENTRATE.